An access switch, or an edge switch, is an electronic device that provides connectivity between computers and computer networks. For example, a host computer can use an access switch to communicate with another computer in a network, such as a local area network (LAN), or other external networks, such as the Internet. Access switches have two levels of operation, the control plane and the data plane. The data plane is responsible for receiving data packets from the host computer and forwarding the packets to other switches or network devices. The control plane is responsible for managing addresses within the network and communications protocols. For example, a control plane query packet can be sent from a host computer that is encoded in a particular communications protocol. The control plane of the access switch can interpret the query packet and send an appropriate response. Communications protocols are systems of digital message formats and rules for exchanging messages between computing systems.
The software of the control plane may be upgraded. During an upgrade of the control plane, the access switch cannot provide control plane service for the host computer so an end user on the host network will experience a network service disruption. One possible solution is to reprogram the operating system kernel of each host computer to respond to a notification of a control plane software upgrade by an access switch by, for example, adjusting the timeouts of various communications protocols. Thus, during the interim period, a host computer avoids sending any control plane messages to the access switch. However, kernels in different host computers are not standardized and so it is difficult and time-consuming to reprogram all the kernels.